You use lookups admin to add and maintain the values available against Core+ fields. You can add a new lookup value so it becomes selectable when you record information.
Click the Administration menu set, then click Lookups Admin.
Click the required lookup to drill down into its lookup value table.
Click New.
Enter a unique Code, then enter a Description.
Click Save, then click Back to Lookup Values List or click Exit to return to the lookup values.
When entering the code in step four, be aware it’s an alphanumeric field and must not contain any spaces.
Your new lookup value is now selectable within the Lookup Selection.